Use a colander to rinse the pinto beans with water.
Put the beans into a LARGE bowl. Fill the bowl with hot water until all the beans are covered. (Be sure there is still room in the bowl for the beans to swell in size.)
Let the beans soak in the water overnight. This process will help remove some "gas" from the beans.
In the morning drain the beans, rinse them in cold water, then put the beans in the crock pot. Add the chicken broth, salt, pepper, garlic, chilies, and the optional cumin. Stir.
Add water to the crock pot until it covers the beans by 1-2 inches. Cook on LOW for 8-9 hours or on HIGH for 4-5 hours.
Serve with a side of cornbread or with any of your favorite Mexican dishes.